In general, in an information processing device equipped with a plurality of secondary battery packs, the plurality of secondary battery packs are defined by name such as “first battery” and “second battery”, and a technology of performing charge and discharge so that the first battery may be preferentially used is employed. The secondary battery pack has such characteristics that deterioration is advanced through the repeated charge and discharge. Thus, if the above-mentioned technology is applied, the first battery is preferentially charged and discharged repeatedly, and hence the first battery deteriorates more as compared with other batteries.
In the case where the information processing device is a product for which the secondary battery packs are easily removed and mounted, it is relatively easy work to replace only a secondary battery pack corresponding to the deteriorated first battery.
However, in the case where the information processing device is an embedded device in which a plurality of secondary battery packs are embedded, the secondary battery packs may not easily be removed and mounted. For such an embedded device, it is desired in view of simple maintenance that the plurality of secondary battery packs become deteriorated at as close to the same level as possible, and the plurality of secondary battery packs can be replaced at the same timing.
Patent Literature 1 (Japanese Unexamined Patent Application Publication (JP-A) No. 2005-168103) discloses in paragraph [0046] that switching control is implemented in a dual battery system so that the numbers of charge/discharge cycles of a main battery 52 and a second battery 53 may be equal to each other.
Patent Literature 1 further discloses in paragraph [0034] that a CPU 120 converts observed voltage and current values into the number of cycles and thereby grasps the number of charge/discharge cycles.